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Method of manufacturing spherical polymer particles from polymer solutions

  • US 4,110,529 A
  • Filed: 11/20/1975
  • Issued: 08/29/1978
  • Est. Priority Date: 11/26/1974
  • Status: Expired due to Term
First Claim
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1. A method of forming a polymeric material into spherical particles or beads, which comprises providing a solution of the polymeric material in a solvent that dissolves the polymeric material without any chemical transformation of the latter;

  • dispersing the resulting polymeric material solution in a liquid dispersing medium that is a non-solvent for the polymeric material and is immiscible with the solvent, the volume ratio of the resulting dispersed phase to the dispersing medium varying from 1;

    1 to 30;

    1, the viscosity of the dispersing medium being no more than about one order less than the viscosity of the dispersed phase;

    adding the resulting emulsion with stirring into an excess of a coagulating liquid that coagulates the polymeric material without any chemical transformation of the latter and that is a non-solvent for the polymeric material, is miscible with the solvent, and is immiscible with the dispersing medium;

    whereupon the mixture is transformed directly into a three phase system of coagulated polymer, the coagulating liquid and the dispersing medium, and thereafter separating the liquid phases and resulting coagulated polymeric material particles or beads.

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